Pantograph



Feb. 26, 1957 c. H. GUISCHARD PANTOGRAPH Filed June 3, 1955 l INVENITOR (Jar/as 1 fiazsrfiaw ffiRNEY A Unit d S ate I PANTOGRAPH' Charles Henry Guischard, Massapequa, N. Y. Application June 3, 1955, Serial No. 513,001

1 Claim. (Cl. 33-25) This invention relates to a pantograph and, more particularly, to means for changing the scale of enlargement or dimensions of a part of a tracing while preserving continuity of line with other, undistorted parts of the same tracing.

The principle of the pantograph is well understood. There is a pivotal mounting of one end of the pantograph, a parallelogram with pivotal corners, a stylus or point mounted at one of the said corners, for tracing the outline of the object to be copies, and an arm or extension of one side of the parallelogram, this extension holding, near the end thereof, a pencil or other writing element for making the enlarged copy of the object being traced by the stylus. This writing element normally is in line with the said pivotal mounting and the stylus.

Briefly stated, this invention comprises means for gradually varying the distance between the writing element and the said mounting. The invention makes possible change of scale of the enlargement of any part of a figure being copied without discontinuity of line at the point at which change of scale begins or ends. It makes possible distortion of any part of a figure being copied as, for example, a feature of the profile of a person while preserving other recognizable features in their true proportions. The invention is useful, therefore, in drawing cartoons and caricatures.

The invention will be illustrated by description in con ncction with the attached drawings.

Fig. 1 is a plan view of my improved pantograph with representation of its use in tracing part of the profile of a person.

Fig. 2 is a side view of the apparatus of Fig. 1.

Fig. 3 is a plan view of a modified form of the invention.

Fig. 4 is a side sectional view on line 4-4 of Fig. 3.

Fig. 5 is a perspective view of the pantograph of Figs. 3 and 4, with the spring omitted.

There are shown the pantograph with the pivotal mounting of an end to a firm support of conventional type (not shown). The frame 12 has several parts all of which are rigid. Portions of these parts 14 meet at pivotal corners. One corner 15 of the parallelogram holds the stylus or tracing point 17.

The side of the parallelogram remote from the pivotal mounting 10 extends as an arm 16 provided with means for attachment to the holder for the pencil or other writing element 18. In the embodiment of Figs. 1 and 2, the holder for the pencil includes a handle 20, rod 22, stop 24 thereon, and spring 26 so mounted, around the rod and between the stop thereon and the sleeve 28 continuous with the element for securing the pencil, that the spring exerts force on the pencil tending to draw it towards its normal position adjacent to its mounting 30 on the said arm.

In the modification shown in Figs. 3-5, spring 32 pulls on the support 34 for the writing element 18 with handle 20. In this modification, however, the spring extends between the pin 40 and the attachment 42 on the support or bar 34 for the pencil or the like.

The bar 34 holding the pencil 18 of Figs. 3-5 is, in fact, an element of the general shape of the extension arm 16, so as to fit slidably within the grooves forming the channel sides 44 constituting the sides of arm 16. Also bar 34 is provided with cut-out or slot 46 through which the pin 40 extends as shown.

It will be observed that the connecting member for securing the writing element or scriber 18 to the arm 16 is shown as the rod 22 of Figs. 1 and 2 and as the bar 34 of Figs. 3-5. The means mounting this member slidably with relation to the arm 16 include the parts 38 and 30 of Figs. 1 and 2 and 40, 44, and 46 of Figs.

The coil spring 26 is mounted with its longitudinal axis generally parallel to the length of the connecting member. Means 28 or 42 and 24 or 40, respectively, establish this spring in fixed relationship at one end to the writing element and at the other end to the said arm.

The operation of the improved pantograph will be largely evident from the description of it that has been given.

In tracing an outline, such as the profile shown in part in Fig. 1, the pantograph is mounted at one end firmly to a support such as a table or drawing board. Then the tracing point 17 is caused, by manual manipulation of the frame, to trace the lines of the profile or other subject to be reproduced, on a different scale, by the writing element 18. As the point 17 moves along the lines of the object being reproduced, the writing point 18 is pressed manually upon paper (not shown) held firmly thereunder. The writing element is thus caused to reproduce the profile. When it is desired to distort the profile, as by enlarging the chin thereof, then tension is placed on the spring 26 or 32, by pulling the handle 20 to the right in the figures and thus moving the writing element 18 farther from the point of support 10. This causes an exaggeration of the scale of the reproduced tracing, as compared to the copy being followed by the point 17. When it is desired to return to the non-distorted reproduction of the profile, then the tension on the spring 26 is gradually relaxed so that the writing point 18 returns to its normal position.

The spring mountings make possible variations of the scale of reproduction in infinitesimal increments with continuity of the lines produced by the writing element. The lengths of rod 22 exposed between the sleeve 28 and stop 24 and slot 44, on the other hand, determine the maximum displacement of the pencil 18 respectively, and therefore the maximum extent of distortion of the final drawing.

When it is desired to return to the normal dimensions in copying, then the tension on spring 32 is gradually released. The copy being made returns to the normal proportion of its dimensions.

The materials of construction are those that are conventional in pantographs with the exception of the springs and extensible holding mechanism for mounting for the writing elements. These may be of materials that are usual for construction of like parts in other arts.

The apparatus is simple in construction and efiective in operation. It gives distorted copies for cartoons and the like quickly, without diflicultly, and without interruption of the lines of the outline at positions at which distortion begins or distortion ends.

It will be understood that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.

3 What I claim is: In a pantograph including elements forming a frame thereof and lying in a plane, pivotal mounting means for one end of the frame, parts of the frame forming a:

parallelogram, means holding the said' parts of the frame pivotally to each other at the corners of the parallelogram, a tracing point, means mounting the tracing point at a corner of the parallelogram, an arm of one of the said elements extending from a corner of the parallelogram remote from the said pivotal mounting means and from the tracing point, a Writing element, and securing means attaching the writing element to the end of the said arm, the improvement comprising a connecting member in the said securing means, means mounting the said member at one end slidably in direction parallel to the said plane of the frame and to the said arm and at the other end in fixed relationship to the writing element, a coil spring disposed with its longitudinal axis generally parallel to and adjacent to the said member and to plane of the said frame, and means establishing the spring in fixed relationship at one end to the writing element and at the other to the end of the said member remote from the writing element, so that the distance of the writing element from the said arm is variable by force applied to the spring and the resulting sliding movement of the said member with respect to the said arm.

References Cited in the file of this patent UNITED STATES PATENTS 695,069 Martin Mar. 11, 1902 809,246 Brown Jan. 2, 1906 2,021,931 Bockius Nov. 26, 1935 2,497,013 Raynes Feb. 7, 1950 FOREIGN PATENTS 395,915 Great Britain July 27, 1933 487,634 Great Britain June 23, 1938 

